Hydrate inhibitor flow profile model for field pipelines

OLGA software proved useful under study of hydrate inhibitor (methanol and diethyleneglycol) flow profile in a field pipeline designed for Cenomanian gas. Inhibitor build-up tends to occur under lower gas rates, in pipeline depression area segments, while inhibitor rate appearing relatively low. The authors show that under liquids accumulation conditions, major inhibitor outflow appears to be extremely uneven, with around several day long periods. Under transition from liquid accumulation to outflow, inhibitor propagation rate tends to rise, followed by steady-state concentration across pipeline length after it is filled by inhibitor. It was found that under liquid accumulation, diethyleneglycol propagation time across the line appears shorter than for methanol in water, while the pipeline filling time remaining immune to inhibitor type under greater gas flow rates.